Merccruiser 7.4 Fan belt replacement on the seawater pump

jpflhr

jpflhr

Member
Oct 2, 2009
31
Lago Vista Texas
Boat Info
2012 Sea Ray 260 Sundeck
Engines
5.0 Mag 300 HP w/ Bravo III
My Fan belt broke connected to the seawater pump and engine and I am trying to figure out how to install new one-- seems no room to get the belt between the 2 pullys on the motor?

I have to pick up a new belt can I buy from a auto parts store and just get a regular 40inch v belt -Quicksiver part # 57-69143Q-- 40inch--
 
A good auto parts place can cross reference the belts to the auto part equivalent.
I just replaced both of mine with ac delco belts.
You need.
Part # 15400.
Its a 3/8 x 40-5/8 vee belt

You have to remove the four bolts on the engine circulating pump to get the belts off. Probly a good idea to replace both while you are at it.
The other one is ac delco # 15480.
Its a 3/8 x 48-5/8 vee belt.

Good luck.
Mark.

Edit. I did not give you the third belt #...as I dont have power steering on mine..sorry.
 
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I've squeezed the belt thru that little gap before, but it wasn't easy and probably not good for the belt. Best to do as stated above and remove the 4 bolts. I like NAPA belts because of the lifetime warranty. You can take your old one in and they will find the right replacement.
 
Guys,
Thanks fore you response and the cross #s for the belts-- So when you say remove the 4 bolts are you talking about the pully on thw engine for the cam shaft? That is were I have issue of putting belt on between Camshaft and crankshaft pullys-- see attachment
The alternator belt no issue with that and the power sterring belt no issue with installing that --

So there are 3 belts correct -- One for alternator one for power sterring and one for seawater pump?

Issue happened when I was on the water after changing alternator just reattached exsisting belt . then engine lost power like out of gas and then i looked and all belts were off pullys with all this black belt stuff on the engine - Only belt left good was the Pw sterring belt -- Shreaded and broke alternator belt and the seawater belt?

View attachment 11267
 
3 belts.Do them all at once and it's rather easy.

I pull the pulley off the intake water pump.I leave the adjuster alone.It's always tight.

The power steering is always an adjustment.I guess its the length and angle.The water/alt/crank belt needs adjustment rarely.

Take the belts tot he auto parts store and match them up.Length and thickness.You'll get all 3 for one from the boat dealer.

Black residue is from a loose belt or locked up pulley/bearing.be a good idea to spin each to feel them.

You won't spin the intake water pump.
 
Thanks,
Yes the 3 belts I have aeady have now and tomorrow AM hope to do the job if its not to hot here LOL
but issue is the the pulleys on the engine getting the belt between them do not see any way but to remove camhaft pulley--? Is this what you mean by removing intake water pump?
 
Lets get this straight 1st.
3 belts.
1..Power steering.It goes power steering to crank.
2..Alternator/circulating water pump/crank
3..Bravo water intake pump

1..The power steering is 1st.It wraps the power steering pulley and the crank.It comes off 1st.Adjuster behind power steering pump.

2..The circulating water pump pulley pops off next BUT that belt is BEHIND the Bravo water pump.Just take off the pulley and then take off the Bravo pump belt.

3..Pull the circulating pump belt off.The Alternator is the adjuster fro this belt.

re-assemble is reverse order.Run for a few minutes and then check tension.They should be firm and move about an inch or so with light pressure.They also should not jump around when the engine is running.
There is no cam shaft pulley.You have 2 water pumps.The 1 in the lower corner is the intake pump.It pulls water from outside the boat.The 2nd one is a circulating pump for the engine.That is the pulley you take off to get the belt on for the intake pump.

It's easier to take off the lower intake water pump pulley than to mess with the adjusting arm behind the pump.4 bolts and it slips off a little tab on the shaft.You'll understand when you take it off.When you put the new belt on you just slip the belt over the pulley THEN put the pulley on the shaft.Use a pick or awl to line the bolts holes up with the pulley.That's that hardest part and it's not hard at all.

The circulating pump pulley comes off the same way.When you take that pulley off you'll be able to slip the intake water pump belt on.

I hope this is what you're asking.
 
There is no pulley on the "camshaft", the camshaft is driven by the timing chain. Dont know about a stern drive but on my inboards the only way to get the belt off is the remove the pulley from the engine mounted coolant circulation pump. This is done by removing 4 bolts that I think are 5/8". Once the pulley comes off then the belt will come off. There is not adquate clearance between the pulley on the crank shaft and the pulley on the circulation pump to remove the belt.
 
i just did this job on my 7.4 [ no power steering } i just loosened the 4 bolt on the ciruclating pump and was able to pry it out enough to slip the bent in , no problem . I did not take the pully off so i did not have to retention tention the other belt.
 
All Thanks for your help I think I do underestand and will be going to do this today--
Will let you all know how it gos
Thanks
 
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